Positioning devices find a wide range of commercial applications, such as surveillance, robotics, and aiming of light emitters such as lasers or searchlights, weaponry, antennae, and radar dishes. Linear positioners or actuators are used for push/pull movement of an object while non-linear positioners are used for pitch/tilt, yaw/pan, and roll movement of an object. The most popular and well-known non-linear positioners are robot wrist and arm devices, such as the type found in U.S. Pat. No. 4,686,866 and camera positioning devices, such as the type found in U.S. Pat. No. 5,028,997.
U.S. Pat. No. 4,686,866 discloses a robotic wrist/arm device having mechanical joints located in the wrist of the robot arm for simultaneous pitch, yaw, and roll movement. The drives for the mechanical joints are located externally from the wrist in the robot arm. This design unnecessarily increases the size of the robotic wrist/arm device and unnecessarily increases the moment arms between the drives and the mechanical joints used to impart motion to the object to be positioned.
U.S. Pat. No. 5,028,997 discloses a camera positioning device for imparting yaw/pan and pitch/tilt motion to a camera and lens assembly located in the actuator or wrist of the device. While one of the drives for positioning the camera is located internally within the wrist of the device, the other drive is located externally from the wrist and is mounted to a base. Again, the externally located second drive unnecessarily increases the size of the camera positioning device.
Accordingly, one of the objects of the present invention is to provide a positioning device which imparts at least yaw and pitch movement to an object wherein the drives are located internally within the wrist or actuator to miniaturize the positioning device as much as possible.